Bump default doctest version to 0.24 #795
Description
The current default version 0.22 is too old for GHC 9.12:
https://github.com/kcsongor/generic-lens/actions/runs/17204241817/job/48801218470?pr=170
rejecting: doctest; 0.24.2, 0.24.1, 0.24.0, 0.23.0 (constraint from command line flag requires ^>=0.22.0)
[__0] trying: doctest-0.22.10
[__1] next goal: ghc (dependency of doctest)
[__1] rejecting: ghc-9.12.2/installed-9b33 (conflict: doctest => ghc>=8.0 && <9.12)